On a Free-swimming Hydroid, Pelagohydra 

 mirabilis, n. gen. et sp. 



By 



Aitliui' Deiidy, D.Sc, F.L.S., 

 Professor of Biology in tlie Canterbury College, University of New Zealand. 



1. Inteoduction. 



The remarkable organism which forms the subject of the 

 present memoir was picked up by myself on the sandy beach 

 at Sumner, a small watering-place near Christchurch, on the 

 east coast of the South Island of New Zealand. One evening 

 in October last (1901), while walking on the shore, I saw 

 lying at my feet a small gelatinous object which had 

 evidently just been thrown up by the tide. On placing it in 



VOL. 46, PART 1. — new series. A 



